U.S. patent number 11,081,860 [Application Number 16/835,803] was granted by the patent office on 2021-08-03 for integrated broadband chaotic semiconductor laser using optical microcavities.
This patent grant is currently assigned to TAIYUAN UNIVERSITY OF TECHNOLOGY. The grantee listed for this patent is TAIYUAN UNIVERSITY OF TECHNOLOGY. Invention is credited to Yuanyuan Guo, Anbang Wang, Longsheng Wang, Yixuan Wang, Yuncai Wang, Tong Zhao.
United States Patent |
11,081,860 |
Wang , et al. |
August 3, 2021 |
Integrated broadband chaotic semiconductor laser using optical
microcavities
Abstract
The present invention discloses an integrated broadband chaotic
semiconductor laser using optical microcavities. The arc-shaped
hexagonal laser outputs light. Part of the light is totally
reflected through the deformed microcavity and then reflected out
of the deformed microcavity from the passive waveguide II; after
entering the passive feedback waveguide, another part of the light
is fed back into the deformed microcavity by the high reflection
film, passes through an in-cavity ray track and then is also
reflected out of the deformed microcavity from the passive
waveguide II; the two-path light is coupled into the arc-shaped
hexagonal laser, and finally generated chaotic laser light is
directionally coupled and output through the passive waveguide I at
the other end of the arc-shaped hexagonal laser. The present
invention has wide broadband, flat spectrum, compact structure, and
no time delay signature.
Inventors: |
Wang; Anbang (Taiyuan,
CN), Wang; Yixuan (Taiyuan, CN), Wang;
Yuncai (Taiyuan, CN), Guo; Yuanyuan (Taiyuan,
CN), Wang; Longsheng (Taiyuan, CN), Zhao;
Tong (Taiyuan, CN) |
Applicant: |
Name |
City |
State |
Country |
Type |
TAIYUAN UNIVERSITY OF TECHNOLOGY |
Taiyuan |
N/A |
CN |
|
|
Assignee: |
TAIYUAN UNIVERSITY OF
TECHNOLOGY (Shanxi, CN)
|
Family
ID: |
1000005717833 |
Appl.
No.: |
16/835,803 |
Filed: |
March 31, 2020 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20200313386 A1 |
Oct 1, 2020 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01S
5/026 (20130101); H01S 5/146 (20130101); H01S
5/1042 (20130101); H01S 5/142 (20130101); H01S
5/1025 (20130101); H01S 5/1021 (20130101); H01S
5/0207 (20130101) |
Current International
Class: |
H01S
5/00 (20060101); H01S 5/10 (20210101); H01S
5/026 (20060101); H01S 5/14 (20060101); H01S
5/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
A Argyris, et al; "Photonic Integrated Device for Chaos
Applications in Communications"; Physical Review Letters (PRL-100)
dated May 16, 2008; pp. 194101-1 through 194101-4. cited by
applicant .
Qinghai Song et al; "Channeling Chaotic Rays into Waveguides for
Efficient Collection of Microcavity Emission"; Physical Review
Letter 108, published Jun. 15, 2012; pp. 1-5. cited by applicant
.
First Office Action issued in Chinese Appln. No. 201910257833.9
dated May 8, 2020. cited by applicant.
|
Primary Examiner: Park; Kinam
Attorney, Agent or Firm: Bacon & Thomas, PLLC
Claims
What is claimed is:
1. An integrated broadband chaotic semiconductor laser using
optical microcavities, comprising an arc-shaped hexagonal laser (2)
and a deformed microcavity (4), wherein one end of the arc-shaped
hexagonal laser (2) is connected with one end of the deformed
microcavity (4) through a passive waveguide II (3), the other end
of the deformed microcavity (4) is connected with a passive
feedback waveguide (5), an end face of the passive feedback
waveguide (5) is coated with a high reflection film, and the other
end of the arc-shaped hexagonal laser (2) is connected with a
passive waveguide I (1).
2. A method for light output of the integrated broadband chaotic
semiconductor laser using optical microcavities according to claim
1, wherein the arc-shaped hexagonal laser (2) outputs light, and
the light is coupled into the deformed microcavity (4) through the
passive waveguide II (3); part of the light is totally reflected
through the deformed microcavity (4) and then reflected out of the
deformed microcavity (4) from the passive waveguide II (3); after
entering the passive feedback waveguide (5), another part of the
light is fed back into the deformed microcavity (4) by the high
reflection film, passes through an in-cavity ray track and then is
also reflected out of the deformed microcavity (4) from the passive
waveguide II (3); the two-path light is coupled into the arc-shaped
hexagonal laser (2), and finally generated chaotic laser light is
directionally coupled and output through the passive waveguide I
(1) at the other end of the arc-shaped hexagonal laser (2).
Description
TECHNICAL FIELD
The present invention relates to the technical field of photonic
integrated chaotic semiconductor lasers, and in particular, to an
integrated broadband chaotic semiconductor laser using optical
microcavities.
BACKGROUND
As a novel and important scientific research tool, chaotic lasers
have been widely used. As a special output form of the laser,
chaotic laser light features randomness, wide spectrum, etc.
Research in recent ten years shows that chaotic laser light has
shown important application value in the fields of chaotic
synchronization and secure optical communication, high-speed random
number key generation, laser radar, fiber network fault detection,
ultra-broadband technology, distributed fiber sensing, etc. The
semiconductor laser has become the key device for generating
chaotic laser due to its small size, light weight, high conversion
efficiency, long service life, easiness in integration, etc.
Methods for generating chaotic laser light by the semiconductor
laser include an optical feedback mode, an optical injection mode,
a photoelectric feedback mode and a hybrid disturbance mode. In the
optical feedback mode, the structure is simple and high-dimensional
broadband chaotic oscillation is generated more easily; therefore,
the use of an optical feedback semiconductor laser to generate
chaotic laser light has become a hot spot for researchers. However,
most of the current methods are implemented by using semiconductor
lasers and external discrete optical elements (an external cavity
length is several meters to tens of meters), which are bulky,
complex in structure, vulnerable to external environment and
unstable in output. Compared with an apparatus composed of discrete
devices, an integrated chip is smaller in size, lower in cost,
better in stability and suitable for mass production, and is
concerned by research institutes in many countries.
In 2008, the PICASSO project of the EU's 6th Framework Programme
developed the first photonic integrated chaotic external cavity
feedback semiconductor laser. In 2010, Annovazzi-Lodi et al. of
University of Pavia in Italy, Mirasso et al. of the University of
the Balearic Islands in Spain and Hamacher of Fraunhofer Institute
of Telecommunications of Fraunhofer Heinrich Hertz Institute in
Germany developed a dual-feedback photonic integrated chaotic
semiconductor laser with an air gap. In 2013, the research group of
Xia Guangqiong of Southwest University and the Key Laboratory of
Semiconductor Materials Science of Chinese Academy of Sciences
jointly developed a monolithic integrated semiconductor laser chip
for generating chaotic laser light, etc.
However, the foregoing photonic integrated chaotic semiconductor
lasers all adopt a delayed optical feedback structure of a DFB
laser, and the generated chaotic laser light has obvious time delay
signature, i.e., chaotic signals have certain periodicity. In
addition, due to the relaxation oscillation of the laser, energy of
the chaotic signals generated by the optical feedback semiconductor
laser is mainly concentrated near the relaxation oscillation
frequency in the frequency domain, resulting in uneven frequency
spectrum, serious low frequency inhibition and narrow bandwidth,
which is not conducive to practical application. In summary, there
is a great need for a laser that features broadband, flat spectrum,
compact structure and no time delay signature.
SUMMARY
At present, most of photonic integrated chaotic semiconductor
lasers adopt a delayed optical feedback structure of a DFB laser,
and generated chaotic laser light has obvious time delay signature.
The DFB laser has relatively low relaxation oscillation frequency,
and greater response to the relaxation oscillation frequency than
other frequencies, resulting in uneven spectrum and low effective
bandwidth of chaotic signals. At present, the length of a
monolithic integrated external cavity needs to be at least about 1
cm, which is not conducive to practical application. In order to
solve the foregoing problems, an integrated broadband chaotic
semiconductor laser using optical microcavities is provided.
The present invention is realized through the following technical
solution: an integrated broadband chaotic semiconductor laser using
optical microcavities, including an arc-shaped hexagonal laser and
a deformed microcavity, where one end of the arc-shaped hexagonal
laser is connected with one end of the deformed microcavity through
a passive waveguide II, the other end of the deformed microcavity
is connected with a passive feedback waveguide, an end face of the
passive feedback waveguide is coated with a high reflection film,
and the other end of the arc-shaped hexagonal laser is connected
with a passive waveguide I.
A method for light output of the integrated broadband chaotic
semiconductor laser using optical microcavities specifically
includes the following steps of: outputting light by the arc-shaped
hexagonal laser, coupling the output light into the deformed
microcavity through the passive waveguide II, totally reflecting
part of the light through the deformed microcavity and then
reflecting the part of the light out of the deformed microcavity
from the passive waveguide II; after another part of the light
enters the passive feedback waveguide, feeding the light back into
the deformed microcavity by the high reflection film, also
reflecting the light out of the deformed microcavity from the
passive waveguide II after the light passes through an in-cavity
ray track, coupling the two-path light into the arc-shaped
hexagonal laser, and directionally coupling and outputting finally
generated chaotic laser light through the passive waveguide I at
the other end of the arc-shaped hexagonal laser.
The integrated chaotic semiconductor laser of the present invention
features wide bandwidth, flat spectrum, compact structure, and no
time delay signature. The integrated chaotic semiconductor laser
internally includes the arc-shaped hexagonal laser and the deformed
microcavity. The conventional arc-shaped hexagonal laser features
large relaxation oscillation frequency and a flat curve of small
signal modulation response, and can eliminate the limitation of the
relaxation oscillation frequency on the bandwidth. An arc edge
hexagonal single-mode semiconductor laser with the microcavity has
a relaxation oscillation frequency of about 11 GHz, and a flat
small signal modulation response curve. Under a certain working
current, a single-mode output with a modulation bandwidth of 13 GHz
is obtained (Optics Letters, 42(7): 1309-1312, 2017). The deformed
microcavity is a variant of a circular optical microcavity with
certain deformation. A light field inside the ideal circular
optical microcavity is in an echo wall mode, while the slightly
deformed circular cavity generates complex ray states, and presents
periodic orbits with different ray angles [Journal of the Optical
Society of America B, 21(5): 923-934, 2004]. Therefore, the
deformed microcavity in the present invention has some slight
deformation based on the circular cavity, and is not limited to the
deformation, thereby presenting periodic orbits with different ray
angles. The arc-shaped hexagonal laser and the deformed microcavity
are connected and coupled through the passive waveguide II to form
an integrated laser, and the other end of the arc-shaped hexagonal
laser is connected with the passive waveguide I to output final
chaotic laser light. The other end of the deformed microcavity is
connected with the passive feedback waveguide. The end face of the
passive feedback waveguide is coated with the high reflection film
for feeding back light into the deformed microcavity. The
arc-shaped hexagonal laser outputs light, the light is coupled into
the deformed microcavity through the passive waveguide II, passes
through the ray track in the deformed microcavity and then is
reflected out of the deformed microcavity from the passive
waveguide II, and this is part of feedback light. Another part of
the light enters the passive feedback waveguide. Since the end face
of the passive feedback waveguide is coated with the high
reflection film, the high reflection film feeds back this part of
the light into the deformed microcavity, and then after passing
through the ray track in the cavity, this part of the light is also
reflected out of the deformed microcavity from the passive
waveguide II to form an optical feedback. The two parts of the
light are integrally coupled into the arc-shaped hexagonal laser,
and the finally generated chaotic laser light is directionally
coupled and output from the passive waveguide I to obtain the
chaotic laser light with wide bandwidth, flat spectrum and no time
delay signature.
Compared with the prior art, the integrated broadband chaotic
semiconductor laser using optical microcavities according to the
present invention can easily generate chaos in an optical feedback
mode. A DFB laser has a low relaxation oscillation frequency
(several GHz), and greater response to relaxation oscillation
frequency than other frequencies, so that the chaotic dynamic is
dominated by relaxation oscillation frequency, the spectrum is
uneven and the effective bandwidth is low. Taiyuan University of
Technology has proposed a method for generating chaotic laser light
without time delay signature and with flat spectrum and wide
bandwidth by a photonic integrated chaotic semiconductor laser (CN
201410435033.9), which generates chaotic laser light by mutual
light injection mainly through left and right distributed feedback
semiconductor laser chips. In contrast, in the present invention,
the arc edge hexagonal single-mode semiconductor laser with the
microcavity is used as a non-linear device and first replaces a DFB
semiconductor laser to generate a chaotic light source by using the
characteristics of large relaxation oscillation frequency and a
flat curve of a small signal modulation response curve, thereby
solving the problem that the relaxation oscillation frequency
limits the bandwidth. Compared with a mirror delayed optical
feedback, an external feedback is constructed by using a
two-dimensional optical microcavity, light is totally reflected in
the cavity many times, and a large optical path can be obtained
with a small geometric size to achieve a long cavity feedback.
Compared with that of the patent with light injection (CN
201410435033.9), the long cavity feedback induces a large number of
external cavity modes and is more prone to chaos. Deformation is
introduced into the microcavity, and randomly distributed feedback
paths are formed by complex ray dynamics of the deformed
microcavity, namely different total reflection paths of light in
the deformed microcavity. This can eliminate the resonance
characteristics of the external cavity, the generated chaotic laser
light has high complexity, and the bandwidth is 20 GHz or more.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic structural diagram of the present invention;
and
FIG. 2 shows an exemplary diagram of a deformed microcavity and its
optical feedback path according to the present invention.
In the figure: 1: passive waveguide I, 2: arc-shaped hexagonal
laser, 3: passive waveguide II, 4: deformed microcavity, 5: passive
feedback waveguide.
DETAILED DESCRIPTION
Specific examples of the present invention are described below with
reference to the accompanying drawings.
As shown in FIG. 1, an integrated broadband chaotic semiconductor
laser using optical microcavities includes, an arc-shaped hexagonal
laser 2 and a deformed microcavity 4, where one end of the
arc-shaped hexagonal laser 2 is connected with one end of the
deformed microcavity 4 through a passive waveguide II 3, the other
end of the deformed microcavity 4 is connected with a passive
feedback waveguide 5, an end face of the passive feedback waveguide
5 is coated with a high reflection film, and the other end of the
arc-shaped hexagonal laser 2 is connected with a passive waveguide
I 1.
A method for light output of the integrated broadband chaotic
semiconductor laser using optical microcavities specifically
includes the following steps of: outputting light by the arc-shaped
hexagonal laser 2, coupling the output light into the deformed
microcavity 4 through the passive waveguide II 3, totally
reflecting part of the light through the deformed microcavity 4 and
then reflecting the part of the light out of the deformed
microcavity 4 from the passive waveguide II 3; after another part
of the light enters the passive feedback waveguide 5, feeding the
light back into the deformed microcavity 4 by the high reflection
film, also reflecting the light out of the deformed microcavity 4
from the passive waveguide II 3 after the light passes through an
in-cavity ray track, coupling the two-path light into the
arc-shaped hexagonal laser 2, and directionally coupling and
outputting finally generated chaotic laser light through the
passive waveguide I 1 at the other end of the arc-shaped hexagonal
laser 2.
The specific operation of this example is as follows: the
arc-shaped hexagonal laser 2 outputs light, the light is coupled
into the deformed microcavity 4 through the passive waveguide II 3,
part of the light is totally reflected through the deformed
microcavity 4 and then reflected out of the deformed microcavity 4
from the passive waveguide II 3, and this is part of feedback
light; another part of the light enters the passive feedback
waveguide 5; since the end face of the passive feedback waveguide 5
is coated with the high reflection film, the high reflection film
feeds this part of the light back into the deformed microcavity 4,
and the light passes through the in-cavity ray track and then is
also reflected out of the deformed microcavity 4 from the passive
waveguide II 3 to form an optical feedback (an in-cavity light ray
track is shown in FIG. 2); the two parts of the light are
integrally coupled into the arc-shaped hexagonal laser 2, and the
finally generated chaotic laser light is directionally coupled and
output from the passive waveguide I 1.
The claimed scope of the present invention is not limited to the
foregoing specific implementations, and the present invention may
have a variety of variations and modifications for those skilled in
the art. All modifications, improvements and equivalent
replacements made within the conception and principles of the
present invention shall be included in the protection scope of the
present invention.
* * * * *